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1/*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26/*
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2012, Intel Corporation.
31 */
32/*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * String manipulation functions.
37 *
38 * libcfs/libcfs/libcfs_string.c
39 *
40 * Author: Nathan Rutman <nathan.rutman@sun.com>
41 */
42
43#include "../../include/linux/libcfs/libcfs.h"
44
45/* Convert a text string to a bitmask */
46int cfs_str2mask(const char *str, const char *(*bit2str)(int bit),
47		 int *oldmask, int minmask, int allmask)
48{
49	const char *debugstr;
50	char op = 0;
51	int newmask = minmask, i, len, found = 0;
52
53	/* <str> must be a list of tokens separated by whitespace
54	 * and optionally an operator ('+' or '-').  If an operator
55	 * appears first in <str>, '*oldmask' is used as the starting point
56	 * (relative), otherwise minmask is used (absolute).  An operator
57	 * applies to all following tokens up to the next operator. */
58	while (*str != 0) {
59		while (isspace(*str))
60			str++;
61		if (*str == 0)
62			break;
63		if (*str == '+' || *str == '-') {
64			op = *str++;
65			if (!found)
66				/* only if first token is relative */
67				newmask = *oldmask;
68			while (isspace(*str))
69				str++;
70			if (*str == 0)	  /* trailing op */
71				return -EINVAL;
72		}
73
74		/* find token length */
75		for (len = 0; str[len] != 0 && !isspace(str[len]) &&
76		      str[len] != '+' && str[len] != '-'; len++);
77
78		/* match token */
79		found = 0;
80		for (i = 0; i < 32; i++) {
81			debugstr = bit2str(i);
82			if (debugstr != NULL &&
83			    strlen(debugstr) == len &&
84			    strncasecmp(str, debugstr, len) == 0) {
85				if (op == '-')
86					newmask &= ~(1 << i);
87				else
88					newmask |= (1 << i);
89				found = 1;
90				break;
91			}
92		}
93		if (!found && len == 3 &&
94		    (strncasecmp(str, "ALL", len) == 0)) {
95			if (op == '-')
96				newmask = minmask;
97			else
98				newmask = allmask;
99			found = 1;
100		}
101		if (!found) {
102			CWARN("unknown mask '%.*s'.\n"
103			      "mask usage: [+|-]<all|type> ...\n", len, str);
104			return -EINVAL;
105		}
106		str += len;
107	}
108
109	*oldmask = newmask;
110	return 0;
111}
112
113/* get the first string out of @str */
114char *cfs_firststr(char *str, size_t size)
115{
116	size_t i = 0;
117	char  *end;
118
119	/* trim leading spaces */
120	while (i < size && *str && isspace(*str)) {
121		++i;
122		++str;
123	}
124
125	/* string with all spaces */
126	if (*str == '\0')
127		goto out;
128
129	end = str;
130	while (i < size && *end != '\0' && !isspace(*end)) {
131		++i;
132		++end;
133	}
134
135	*end= '\0';
136out:
137	return str;
138}
139EXPORT_SYMBOL(cfs_firststr);
140
141char *
142cfs_trimwhite(char *str)
143{
144	char *end;
145
146	while (isspace(*str))
147		str++;
148
149	end = str + strlen(str);
150	while (end > str) {
151		if (!isspace(end[-1]))
152			break;
153		end--;
154	}
155
156	*end = 0;
157	return str;
158}
159EXPORT_SYMBOL(cfs_trimwhite);
160
161/**
162 * Extracts tokens from strings.
163 *
164 * Looks for \a delim in string \a next, sets \a res to point to
165 * substring before the delimiter, sets \a next right after the found
166 * delimiter.
167 *
168 * \retval 1 if \a res points to a string of non-whitespace characters
169 * \retval 0 otherwise
170 */
171int
172cfs_gettok(struct cfs_lstr *next, char delim, struct cfs_lstr *res)
173{
174	char *end;
175
176	if (next->ls_str == NULL)
177		return 0;
178
179	/* skip leading white spaces */
180	while (next->ls_len) {
181		if (!isspace(*next->ls_str))
182			break;
183		next->ls_str++;
184		next->ls_len--;
185	}
186
187	if (next->ls_len == 0) /* whitespaces only */
188		return 0;
189
190	if (*next->ls_str == delim) {
191		/* first non-writespace is the delimiter */
192		return 0;
193	}
194
195	res->ls_str = next->ls_str;
196	end = memchr(next->ls_str, delim, next->ls_len);
197	if (end == NULL) {
198		/* there is no the delimeter in the string */
199		end = next->ls_str + next->ls_len;
200		next->ls_str = NULL;
201	} else {
202		next->ls_str = end + 1;
203		next->ls_len -= (end - res->ls_str + 1);
204	}
205
206	/* skip ending whitespaces */
207	while (--end != res->ls_str) {
208		if (!isspace(*end))
209			break;
210	}
211
212	res->ls_len = end - res->ls_str + 1;
213	return 1;
214}
215
216/**
217 * Converts string to integer.
218 *
219 * Accepts decimal and hexadecimal number recordings.
220 *
221 * \retval 1 if first \a nob chars of \a str convert to decimal or
222 * hexadecimal integer in the range [\a min, \a max]
223 * \retval 0 otherwise
224 */
225int
226cfs_str2num_check(char *str, int nob, unsigned *num,
227		  unsigned min, unsigned max)
228{
229	char	*endp;
230
231	str = cfs_trimwhite(str);
232	*num = strtoul(str, &endp, 0);
233	if (endp == str)
234		return 0;
235
236	for (; endp < str + nob; endp++) {
237		if (!isspace(*endp))
238			return 0;
239	}
240
241	return (*num >= min && *num <= max);
242}
243
244/**
245 * Parses \<range_expr\> token of the syntax. If \a bracketed is false,
246 * \a src should only have a single token which can be \<number\> or  \*
247 *
248 * \retval pointer to allocated range_expr and initialized
249 * range_expr::re_lo, range_expr::re_hi and range_expr:re_stride if \a
250 `* src parses to
251 * \<number\> |
252 * \<number\> '-' \<number\> |
253 * \<number\> '-' \<number\> '/' \<number\>
254 * \retval 0 will be returned if it can be parsed, otherwise -EINVAL or
255 * -ENOMEM will be returned.
256 */
257static int
258cfs_range_expr_parse(struct cfs_lstr *src, unsigned min, unsigned max,
259		     int bracketed, struct cfs_range_expr **expr)
260{
261	struct cfs_range_expr	*re;
262	struct cfs_lstr		tok;
263
264	LIBCFS_ALLOC(re, sizeof(*re));
265	if (re == NULL)
266		return -ENOMEM;
267
268	if (src->ls_len == 1 && src->ls_str[0] == '*') {
269		re->re_lo = min;
270		re->re_hi = max;
271		re->re_stride = 1;
272		goto out;
273	}
274
275	if (cfs_str2num_check(src->ls_str, src->ls_len,
276			      &re->re_lo, min, max)) {
277		/* <number> is parsed */
278		re->re_hi = re->re_lo;
279		re->re_stride = 1;
280		goto out;
281	}
282
283	if (!bracketed || !cfs_gettok(src, '-', &tok))
284		goto failed;
285
286	if (!cfs_str2num_check(tok.ls_str, tok.ls_len,
287			       &re->re_lo, min, max))
288		goto failed;
289
290	/* <number> - */
291	if (cfs_str2num_check(src->ls_str, src->ls_len,
292			      &re->re_hi, min, max)) {
293		/* <number> - <number> is parsed */
294		re->re_stride = 1;
295		goto out;
296	}
297
298	/* go to check <number> '-' <number> '/' <number> */
299	if (cfs_gettok(src, '/', &tok)) {
300		if (!cfs_str2num_check(tok.ls_str, tok.ls_len,
301				       &re->re_hi, min, max))
302			goto failed;
303
304		/* <number> - <number> / ... */
305		if (cfs_str2num_check(src->ls_str, src->ls_len,
306				      &re->re_stride, min, max)) {
307			/* <number> - <number> / <number> is parsed */
308			goto out;
309		}
310	}
311
312 out:
313	*expr = re;
314	return 0;
315
316 failed:
317	LIBCFS_FREE(re, sizeof(*re));
318	return -EINVAL;
319}
320
321/**
322 * Matches value (\a value) against ranges expression list \a expr_list.
323 *
324 * \retval 1 if \a value matches
325 * \retval 0 otherwise
326 */
327int
328cfs_expr_list_match(__u32 value, struct cfs_expr_list *expr_list)
329{
330	struct cfs_range_expr	*expr;
331
332	list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
333		if (value >= expr->re_lo && value <= expr->re_hi &&
334		    ((value - expr->re_lo) % expr->re_stride) == 0)
335			return 1;
336	}
337
338	return 0;
339}
340
341/**
342 * Convert express list (\a expr_list) to an array of all matched values
343 *
344 * \retval N N is total number of all matched values
345 * \retval 0 if expression list is empty
346 * \retval < 0 for failure
347 */
348int
349cfs_expr_list_values(struct cfs_expr_list *expr_list, int max, __u32 **valpp)
350{
351	struct cfs_range_expr	*expr;
352	__u32			*val;
353	int			count = 0;
354	int			i;
355
356	list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
357		for (i = expr->re_lo; i <= expr->re_hi; i++) {
358			if (((i - expr->re_lo) % expr->re_stride) == 0)
359				count++;
360		}
361	}
362
363	if (count == 0) /* empty expression list */
364		return 0;
365
366	if (count > max) {
367		CERROR("Number of values %d exceeds max allowed %d\n",
368		       max, count);
369		return -EINVAL;
370	}
371
372	LIBCFS_ALLOC(val, sizeof(val[0]) * count);
373	if (val == NULL)
374		return -ENOMEM;
375
376	count = 0;
377	list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
378		for (i = expr->re_lo; i <= expr->re_hi; i++) {
379			if (((i - expr->re_lo) % expr->re_stride) == 0)
380				val[count++] = i;
381		}
382	}
383
384	*valpp = val;
385	return count;
386}
387EXPORT_SYMBOL(cfs_expr_list_values);
388
389/**
390 * Frees cfs_range_expr structures of \a expr_list.
391 *
392 * \retval none
393 */
394void
395cfs_expr_list_free(struct cfs_expr_list *expr_list)
396{
397	while (!list_empty(&expr_list->el_exprs)) {
398		struct cfs_range_expr *expr;
399
400		expr = list_entry(expr_list->el_exprs.next,
401				      struct cfs_range_expr, re_link),
402		list_del(&expr->re_link);
403		LIBCFS_FREE(expr, sizeof(*expr));
404	}
405
406	LIBCFS_FREE(expr_list, sizeof(*expr_list));
407}
408EXPORT_SYMBOL(cfs_expr_list_free);
409
410/**
411 * Parses \<cfs_expr_list\> token of the syntax.
412 *
413 * \retval 1 if \a str parses to \<number\> | \<expr_list\>
414 * \retval 0 otherwise
415 */
416int
417cfs_expr_list_parse(char *str, int len, unsigned min, unsigned max,
418		    struct cfs_expr_list **elpp)
419{
420	struct cfs_expr_list	*expr_list;
421	struct cfs_range_expr	*expr;
422	struct cfs_lstr		src;
423	int			rc;
424
425	LIBCFS_ALLOC(expr_list, sizeof(*expr_list));
426	if (expr_list == NULL)
427		return -ENOMEM;
428
429	src.ls_str = str;
430	src.ls_len = len;
431
432	INIT_LIST_HEAD(&expr_list->el_exprs);
433
434	if (src.ls_str[0] == '[' &&
435	    src.ls_str[src.ls_len - 1] == ']') {
436		src.ls_str++;
437		src.ls_len -= 2;
438
439		rc = -EINVAL;
440		while (src.ls_str != NULL) {
441			struct cfs_lstr tok;
442
443			if (!cfs_gettok(&src, ',', &tok)) {
444				rc = -EINVAL;
445				break;
446			}
447
448			rc = cfs_range_expr_parse(&tok, min, max, 1, &expr);
449			if (rc != 0)
450				break;
451
452			list_add_tail(&expr->re_link,
453					  &expr_list->el_exprs);
454		}
455	} else {
456		rc = cfs_range_expr_parse(&src, min, max, 0, &expr);
457		if (rc == 0) {
458			list_add_tail(&expr->re_link,
459					  &expr_list->el_exprs);
460		}
461	}
462
463	if (rc != 0)
464		cfs_expr_list_free(expr_list);
465	else
466		*elpp = expr_list;
467
468	return rc;
469}
470EXPORT_SYMBOL(cfs_expr_list_parse);
471
472/**
473 * Frees cfs_expr_list structures of \a list.
474 *
475 * For each struct cfs_expr_list structure found on \a list it frees
476 * range_expr list attached to it and frees the cfs_expr_list itself.
477 *
478 * \retval none
479 */
480void
481cfs_expr_list_free_list(struct list_head *list)
482{
483	struct cfs_expr_list *el;
484
485	while (!list_empty(list)) {
486		el = list_entry(list->next,
487				    struct cfs_expr_list, el_link);
488		list_del(&el->el_link);
489		cfs_expr_list_free(el);
490	}
491}
492
493int
494cfs_ip_addr_parse(char *str, int len, struct list_head *list)
495{
496	struct cfs_expr_list	*el;
497	struct cfs_lstr		src;
498	int			rc;
499	int			i;
500
501	src.ls_str = str;
502	src.ls_len = len;
503	i = 0;
504
505	while (src.ls_str != NULL) {
506		struct cfs_lstr res;
507
508		if (!cfs_gettok(&src, '.', &res)) {
509			rc = -EINVAL;
510			goto out;
511		}
512
513		rc = cfs_expr_list_parse(res.ls_str, res.ls_len, 0, 255, &el);
514		if (rc != 0)
515			goto out;
516
517		list_add_tail(&el->el_link, list);
518		i++;
519	}
520
521	if (i == 4)
522		return 0;
523
524	rc = -EINVAL;
525 out:
526	cfs_expr_list_free_list(list);
527
528	return rc;
529}
530EXPORT_SYMBOL(cfs_ip_addr_parse);
531
532/**
533 * Matches address (\a addr) against address set encoded in \a list.
534 *
535 * \retval 1 if \a addr matches
536 * \retval 0 otherwise
537 */
538int
539cfs_ip_addr_match(__u32 addr, struct list_head *list)
540{
541	struct cfs_expr_list *el;
542	int i = 0;
543
544	list_for_each_entry_reverse(el, list, el_link) {
545		if (!cfs_expr_list_match(addr & 0xff, el))
546			return 0;
547		addr >>= 8;
548		i++;
549	}
550
551	return i == 4;
552}
553EXPORT_SYMBOL(cfs_ip_addr_match);
554
555void
556cfs_ip_addr_free(struct list_head *list)
557{
558	cfs_expr_list_free_list(list);
559}
560EXPORT_SYMBOL(cfs_ip_addr_free);
561